The transmit coil of a metal detector has self-inductance
PHYSICS · Multi-part · Fermi University Physics · Electricity, Magnetism & Electromagnetism · Electromagnetic induction and alternating-current circuits · Electromagnetic induction and alternating-current circuits
Electricity, Magnetism and Electromagnetism, Ch Transients: RC, RL and LC circuits
Problem
The transmit coil of a metal detector has self-inductance L=330μH. It is to be made to ring at as close to 100.0kHz as possible by connecting a capacitance across it; the coil's resistance is small enough that the ringing frequency may be taken as the undamped natural frequency ω0/2π, and the capacitors are ideal. Only two capacitors are in the parts drawer: 10nF and 22nF. The four possible tanks are: the 10nF alone, the 22nF alone, the two in series, and the two in parallel.
((a)) What capacitance would give exactly 100.0kHz with this coil?
((b)) Which of the four options comes closest to that capacitance? Give its capacitance.
((c)) What natural frequency does the chosen option actually give, and by what percentage does it miss 100.0kHz?